1. Field
The embodiments described below relate generally to imaging using radiation. More particularly, some embodiments concern acquiring an image during a radiotherapy treatment to using the treatment radiation to determine a motion in an area of interest of a subject.
2. Description
Images of internal patient volumes are commonly used in modern medical practice. Such images may be used to generate or confirm a diagnosis and/or to plan a course of treatment. In order to obtain an internal image, a patient is typically irradiated with one or more imaging beams of radiation prior to a treatment session. Images obtained prior to the current treatment session may also be used to aid patient positioning immediately prior to an administration of the radiotherapy treatment.
An important aspect of radiotherapy treatment concerns positioning the subject in the proper location to ensure the accurate delivery of radiation during the treatment session. Conventionally, the volume(s) of interest that will be irradiated during a treatment session are imaged prior to the treatment irradiation in order to accurately ascertain their location within the subject. Disadvantages related to this method, as a sole approach, is the lack of information regarding patient and target information once treatment radiation has been initiated. Thus, it is usually a prescribed protocol only for patient set-up.
In some aspects, treatment radiation may be serially delivered from different angles. Thus, knowledge of patient and target location integrity may be valuable during one of more treatment trajectories. As opposed to utilizing an imaging system stationary to the patient, imaging of the treatment beam offers the most direct form of information regarding the beam/patient relationship.